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Terahertz Gain In A Sige/Si Quantum Staircase Utilizing The Heavy-Hole Inverted Effective Mass, Richard A. Soref, Greg Sun
Terahertz Gain In A Sige/Si Quantum Staircase Utilizing The Heavy-Hole Inverted Effective Mass, Richard A. Soref, Greg Sun
Physics Faculty Publications
Modeling and design studies show that a strain-balanced Si1−xGex/Si superlattice onSi1−yGey-buffered Si can be engineered to give an inverted effective mass HH2 subband adjacent to HH1, thereby enabling a 77 K edge-emitting electrically pumped p–i–pquantum staircase laser for THz emission at energies below the 37 meV Ge–Ge optical phonon energy. Analysis of hole-phonon scattering, lifetimes, matrix elements, and hole populations indicates that a gain of 450 cm−1 will be feasible at f = 7.3 THz during 1.7 kA/cm2 current injection.
Sige/Si Thz Laser Based On Transitions Between Inverted Mass Light-Hole And Heavy-Hole Subbands, L. Friedman, Greg Sun, Richard A. Soref
Sige/Si Thz Laser Based On Transitions Between Inverted Mass Light-Hole And Heavy-Hole Subbands, L. Friedman, Greg Sun, Richard A. Soref
Physics Faculty Publications
We have investigated a SiGe/Si quantum-well laser based on transitions between the light-hole and heavy-hole subbands. The lasing occurs in the region of k space where the dispersion of ground-state light-hole subband is so nonparabolic that its effective mass is inverted. This kind of lasing mechanism makes total population inversion between the two subbands unnecessary. The laser structure can be electrically pumped through tunneling in a quantum cascade scheme. Optical gain as high as 172/cm at the wavelength of 50 μm can be achieved at the temperature of liquid nitrogen, even when the population of the upper laser subband is …